Any gun made in the last 10 years already has the 8.5 lb spring. Call up Kel-tec with the SN and they will send you a spring if your gun is in the pre 8.5 lb range. They will do this for any owner (first or hundredth owner).

Any gun made in the last 10 years already has the 8.5 lb spring. Call up Kel-tec with the SN and they will send you a spring if your gun is in the pre 8.5 lb range. They will do this for any owner (first or hundredth owner).

MN is right on.
I will add that if your serial # is 2500+ or starts with a letter rather than a number, you have the 8.5lb spring.